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ICEBell

ICEBell. Ice Mass Balance in the Bellingshausen Sea James Clark Ross, Nov 2010 Participants BAS (Maksym), SAMS (Wilkinson) WHOI, DTU, U Manitoba,UTSA Partners UCL, DAMTP, UCSC. ICEBell Snow and ice processes, mass balance, and air-ice-ocean interactions in the Bellingshausen Sea.

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ICEBell

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  1. ICEBell Ice Mass Balance in the Bellingshausen Sea James Clark Ross, Nov 2010 Participants BAS (Maksym), SAMS (Wilkinson) WHOI, DTU, U Manitoba,UTSA Partners UCL, DAMTP, UCSC

  2. ICEBellSnow and ice processes, mass balance, and air-ice-ocean interactions in the Bellingshausen Sea

  3. ICEBell • ICEBell Programme • AUV-based 3D ice draft measurements • Airborne topographic mapping (ex Rothera)‏ • In situ snow and ice thickness and properties • Primary Objectives • Snow and sea ice thickness distribution • Cryosat/ICESat algorithms • Snow and ice melt processes • Satellite snow depth Rothera Nominal cruise track (ice condition dependent)‏ Red boxes show primary areas of interest‏

  4. Why the Bellingshausen Sea? • Ice extent has seen the largest declines in the Bellingshausen – declines in ice season length rival those for the Beaufort/Chukchi • Subject to frequent extreme deformational events that impact ice thickness distribution • Has some of the deepest snow cover in the Antarctic – important impacts on flooding and snow ice formation, summer melt processes, and interpretation of satellite altimetry data Ice Concentration Trends September Snow Depth

  5. Ice Thickness Distribution Observed Annual Average • No large-scale detailed measurements of snow and ice thickness distribution in Antarctic • Currently, large discrepancy between in-situ and satellite altimeter estimates • Ice thickness determined primarily from ship-based visual observations • Biased to thin ice areas • Does not adequately account for ridging • Satellite estimates complicated by deep snow cover • large uncertainty in satellite snow depths • Relationship between snow distribution and ice thickness distribution not well known ICESat thickness estimates

  6. ICEBell • ICEBell Programme • AUV-based 3D ice draft measurements • Airborne topographic mapping (ex Rothera)‏ • In situ snow and ice thickness and properties • Primary Objectives • Snow and sea ice thickness distribution • Cryosat/ICESat algorithms • Snow and ice melt processes • Satellite snow depth • Ice-upper ocean interactions Rothera Nominal cruise track (ice condition dependent)‏ Red boxes show primary areas of interest‏

  7. 2002 2003 2004 2005 2006 2007 2008 2009 Nov 5 Ice Conditions Large interannual variability so exact cruise track will be contingent Conditions as of 23/09/10 are similar to 2007 conditions

  8. WHOI SEABed AUV(Hanu Singh) • Floe scale survey (500 x 500 m) ~ 4 hours • 230 kHz multibeam sonar • CTD + ADCP • Microstructure probe • 7-band optical radiometer

  9. Example of ice bottom topography from an AUV multibeam survey Complex ridge system Open Water Courtesy J. Wilkinson

  10. DTU-space Airborne Lidar (BAS/DTU) BAS MASIN twin-otter will overfly sampling sites providing detailed surface topography of ice floes This may occur prior, during or after occupation Riegl Q140/240 scanning lidar Honeywell GPS/INS GPS rcvrs (Javad, Trimble, Ashtech) Provides sea-ice freeboard swaths => Thickness + detailed mapping of ridges and leads Images Courtesy of Rene Forsberg

  11. Surface Characterisation(U of M, BAS, SAMS, UTSA, DRI) • Terrestrial 3D laser mapping of snow surface • EM-31 surveys and conventional drilling • Snow depth distribution, properties and flooding extent (GPR) • Ice structure, properties, biology (coring)

  12. SAMS Ice Mass Balance Buoys • Monitor surface and basal melt • Several spar freeze-in buoys • Provide beacons for Twin over-flights • Some will form arrays for deformation information

  13. Air-ice-ocean interactions • Airborne boundary layer flux measurements from Twin-Otter. (BAS) • Oceanographic observations (CTD) (SAMS/BAS) • Microstructure under melting sea ice (SAMS) Locations of CTD stations occupied in 2007 Blue line is a possible cruise track for JR240

  14. NASA IceBridge flight in support of ICEBellLikely date ~22 Oct Cruise area of interest Flight above is for a “light” ice year. 2010 is likely to be light to moderate. In this case, we will operate more to the west of Alexander Island than to the North

  15. Precise cruise track will depend on ice conditions and success of Twin overflights. The primary criteria are 1) successful completion of surveys and overflights over a range of ice types 2) Penetration into the main ice pack (past the broken ice of the marginal ice zone)

  16. Polarview • Near daily imagery for aiding navigation in ice and cruise track planning • High resolution radar imagery from Envisat and Radarsat-2 (25-100 m resolution) Example subscene of western edge of Charcot Island ~30km x 60 km

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